Multiple spindle broaching lathe indexing mechanism



Oct. 5, 1943. 1 2,330,968

MULTIPLE SPINDLE BROACHING LATHE INDEXING MECHANISM W. F. GROENE ETALOriginal Filed April 30, 1940 12 Sheets-Sheet 1 lllHHli INVENTORS. TW\LL\P-M F- QROENE Oct. 5, 1943. w. F. GROENE ET AL. 2,330,968

MUL'IIFLE SPINDLE BROAGHING LATHE INDEXING MECHANISM Original FiledApril (50, 1940 12 Sheets-Sheet. 2

HG-H' IN VENTORS. \.\J\LL\AM EGROENE HAROLD ISIEKMANN Oct. 5, 1943.

w. F. GROENE ET AL 2,330,968 MULTIPLE SPINDLE BROACHING LATHE iNDEXINGMECHANISM Original Filed April 30, 1940 12 Sheets-Sheet 5 [X P I \so IKEmg \i k k a 163 i FTEIH m-vamoas.

WlL'UAM'F. GROE NE" A HAROLD JESIEKMANNI.

1943. w. F. GROENE ETAL 30 MULTIPLE SPINDLE BROACHING LATHE INDEXINGMECHANISM Original Filed April 50, 1940 12 Sheets-Sheet 4 FT'BJSZ I@INVENTORS.

WILLIAM F. GROENE HAROLD J. SIEKMANN Oct. 5, 1943. w. F. GROENE ET AL2,330,963

MULTIPLE SPINDLE BROACHING LATHE INDEXING MECHANISM Original Filed April50, 1940 12 Sheets-Sheet 5 LDRDlNG STRTWN WHY \NVENTORS.

W\LLIAM F. qRoENE' HAROLD J.SIEKMI\NN Oct. 5, 1943. w. F. GROENE ETAL2,330,968

MULTIPLE SPINDLE B ROACHING LATHE INDEXING MECHANISM Original FiledApril 30, 1940 12 Sheets-Sheet6 INVENTORS. WILUAM F. GROENE HAROLD J.SIEKMANN Oct. 5, 1943. w. F. GROENE ETAL MULTIPLE SPINDLE BRO'ACHINGLATHE INDEXING MECHANISM Original Filed April so. 1940 12 Sheets-Sheet'7 Oct. 5, 1943. w. F. GROENE ETAL 2,330,968

MULTIPLE SPINDLE BROACHING LATHE INDEXING MECHANISM Original Filed April30, 1940 12 Sheets-Sheet a \NVE TORS. WILLIAM F. GROENE HAROLDJ.S|EKMI\NN Oct. 5, 1943. w. F. GROENE ETAL 2,330,968

MULTIPLE SPINDLE BROACHING LATHE INDEXING MECHANISM Original Filed April30, 1940 12 Sheets-Sheet 9 lNVENTORS WILUAM F. GRDENE HAROLD J.$lEKMP\NNi kbmwfi. M

Oct. 5, 1943. w. F. GROENE ETAL MULTIPLE SPINDLE BROACHING LATHEINDEXING MECHANISM Original Filed April 50, 1940 12 Sheets-Sheet l0MULTIPLE SPINDLE BROACHING LATHE INDEXING MECHANISM Oct. 5, 1943. w. F.GROENE EI'AL.

Original Filed April 30, 1940 12 Sheets-Sheet ll m T m I l m f 2 4 a: Gn I. m M 4 I a M: 4 F 15 e X mQX F EED Oct. 5, 1943.

w. F. GROENE ETAL MULTIPLE SPINDLE BROACHING LATHE INDEXING MECHANISMOriginal Filed April .50, 1940 12 Sheets-Sheet 12 INVENTORS. WILLIAM F.CTROENE HAROLD J. SIEK'MANN B Patented Oct. 5, 1943 MULTIPLE SPINDLEBROACHING LATHE INDEXING MECHANISM William F. Grocne and Harold J.Siekmann, Cincinnati, Ohio, assignors to The R. K. Le Blond Machine ToolCompany, Cincinnati, Ohio, a

corporation of Delaware Original application April 30, 1940, Serial No.332,540, now Patent No. 2,280,229, dated April Divided and thisapplication December 24, 1940, Serial No. 371,570

4 Claims.

tions of multi-throw internal combustion engine crankshafts. Moreparticularly, this invention pertains to indexing mechanism for amachine for finish machining the line bearings and associated portionsof such crankshafts by means of a series of progressive metal cuttingoperations undertaken successively by different types of toolapplications to the various bearing portions to be machined. Thisapplication is a divisional application of Serial No. 332,540 filedApril30, 1940, now Patent No. 2,280,229, granted April 21, 1942.

An object of this invention is to provide a series of progressive finishbroaching and shaving steps on the line bearings of a crankshaft wherebysuch bearings may be finished to an extremely high degree of accuracyand in which the runout, that is the concentricity of the machinedbearings relative to the true axis of rotation on the crankshaft, iswell within the limits of rough grinding operations formerly necessaryto accomplish this result.

It is a purpose of this lathe to machine these bearing portions by ametal cutting operation to an accuracy of .001 of an inch run-out orless by means of a series of broaching and shaving tool applications ina progressive manner. This unique arrangement is far superior to roughgrinding operations heretofore undertaken which consume large amounts ofproductive time and are expensive because of the problem of wheel wearand the impracticability of grinding the small protruding surfacesassociated with the line bearings, particularly when required to do soat high productive speeds on a plurality of bearings at the same timewith great accuracy.

An object of this invention is to set forth a multiple spindle indexingmachine in which "a series of progressive broaching and shaving stepsmay be undertaken on the bearing portions of multi-throw crankshafts.

An object of this invention is to chuck the crankshaft and rotate it bysuitable chucking means which supports the ends of the crankshai t oncenters and provides a suitable center drive chucking mechanismintermediate these centers for rotating and supporting the crankshaftduring the machining operations. It is then the object to index thecrankshaft, while so held, to a work station and there to apply broacheswhich may first do broaching operations on certain specific parts of theline bearing portions of the shaft; then to index the crankshaft toanother work station where a second series of breaches may do broachingoperations on other portions of these line bearings; and then finally toindex the crankshaft to a final work station where a series of shavingtools perform the final accurate sizing operations on the diameterportions of the crankshaft bearings.

A further object of this invention i;-; to provide in a multiple spindlebroaching lathe. a rotatable carrier member having a series of Workspindles, each comprising a center drive chucking dcvice and tailstockswith centers mounted on the carrier member and to provide at a series ofwork stages, appropriate broaching tools adapted to engages the workpieces held in the Work spindles of the rotatable carrier member, whichmember may be indexed to bring the work pieces to the various broachingstations during the cutting cycle of the machine.

Another object of this invention is to provide in a multiple spindlebroaching lathe having a rotatable carrier member and a series of workspindles on the carrier member comprising center drive chuckingmechanism and tailstocks with centers for supporting a crankshaft, aseries of work stations to which the crankshaft may be successivelyindexed by rotation of said carrier and at which are located a series ofbroaching cutters and shaving tool cutters for performing variousshaving and broaching operations on the Work piece as it isprogressively indexed through the various work stations.

Another object of this invention is to provide in a multiple spindlebroaching lathe, a series of work stations having a series of broachingcutting devices, and a work carrier member for progressively presentingwork pieces to said Work stations and to provide indexing mechanism foractuating the carrier member whereby at the completion of the machiningoperation at any one stage, the tools are held in led-in position, whilethe work carrier member is partially indexed and then after said workcarrier is partially indexed, the broaching cutters are retracted tofully withdrawn position, whereupon the indexing of said carrier membercontinues to bring the work pieces to the next work station forcontinuation of the cutting cycle.

Further features and advantages of this invention will appear from thedetailed description of the drawings in which:

Figure I is a front elevation of a typical embodiment of our inventionin a multiple spindle broaching lathe.

Figure II is a left hand end elevation of the machine shown in Figure Ias indicated by the line 11-11 of Figures I and IX.

Figure III is a vertical transverse section through the lathe on theline III-III of Figures I and IX.

Figue IV is a right hand end elevation of th machine as indicated by theline IVIV of Figure I.

Figure V is a vertical transverse section through the machine on theline V-V of Figures I, X, XI, and XII.

Figure V1 is an enlarged fragmentary view of a portion of the front ofthe machine shown in Figure I, particularly indicating the arrangementof the control leverfor stopping and starting of the work spindles whenat the loading station as indicated by the line VI-VI on Figures II andVIII.

Figure VII is an enlarged fragmentary view of the cam ends for theclutch shifting rods for varying the spindle speeds and for starting andstopping rotation of the work spindles shown on the line VII-VII inFigure VIII.

Figure VIII is a fragmentary transverse section through the drivingmechanism for the work spindles on the line VIII--VIII in Figures I, VI,VII, and IX, particularly showing the manual control for actuating theclutch shifter rods for spindle stopping and starting the work spindleand for operating them at low and high speeds.

Figure IX is a diagrammatic longitudinal section through the workcarrier drum and driving mechanism for operating the center drive workspindles at low speed and high speed and for arresting rotation of saidspindles shown substantially on the line IX-IX of Figures II and III.

Figure X is a diagrammatic view substantally on the line X-X of FigureV, XV, and XVI showing machining of the line bearing portions of acrankshaft at work station one" where a series of face broaching toolsare simultaneously applied to all of the radially extended surfaces ofthe line bearing portions which have been previously roughed out in aprior operation.

Figure XI is a diagrammatic view substantially on the line XIXI ofFigures V, XVII, and XVIII showing the application of a series ofbroaches simultaneously to all of the diameter portions of the linebearing portions of the crankshaft at station "two.

Figure XII is a diagrammatic view substantially on the line XII-XII ofFigures V, XIII, and XIV, showing the simultaneous application of aseries of shaving tools for the final sizing of the diameter portions ofthe line bearings of the crankshaft being machined at station three.

Figure XIII is a section on the line XIIL-XIII of Figure XII showing theapplication of the shaving tools to the machining of the diameterportions of the line bearings of the crankshaft.

Figure XIV is a plan view on the line X[V,-XIV of Figures XIII.

Figure XV is a plan view of the face broaches shown on the line XV-XV ofFigures V and XVI.

Figure XVI is a section on the XVI-XVI ofbroaching tools for thediameter portions of the line bearings of the crankshaft.

Figure XIX is a diagram showing the electric and hydraulic controlmechanism for the lathe.

General organization As shown in Figure I, the machine comprises a baseI, upon which is mounted the upright supports 2 and 3 and on top ofthese supports is mounted a housing 4 which ties the upper ends of thesesupports together .and holds them in rigid position on the base of themachine. In appropriate bearings 5 and 6, in the respective supports 2and 3 is journaled the work spindle carrying and indexing drum 1 onwhich are mounted a series of center drive chuck housings 8, in whichare journaled approprate center drive ring gears 9 containing centerdrive chucking mechanism l0 and also the cooperating centering devicesor tailstocks l I, having the usual slidably adjustable barrels l2,carrying the centers 13, which engage the ends of the crankshaft C to bemachined in the lathfie, whereby the crankshaft is chucked and rotatedintermediate its ends and supported on its ends by these centers in thetailstocks ll.

Referring particularly to Figure V, a fundamental purpose of the drum 1and associated parts is to index the crankshafts to be machined whilecarried in the center drive chucks l0 and on the centers l3 of thetailstocks l l to a series of three work stations as designated in thisfigure as work station one, work station two, and work station three." Afourth station, at which no cutting is done is designated as the loadingstation and is provided for inserting and removing the crankshafts C toand from the work spindles while the machining operations are takingplace at the other three workstations.

Machining operations to be performed After the work piece or crankshaftC has been loaded in the chucking and centering devices at tendedportions of the line bearings of the crankthe loading station, the drumI rotates in a clockwise direction, as seen in Figure V, carrying thework C into properly indexed position for cutting action at work stationone. It is to be understood that the work crankshaft, which isspecifically illustrated in Figures X, XI, and XII, has been previouslyrough machined on the surfaces to be finished by the various machiningoperations to be undertaken in this machine invention; this previousroughing operation being done on a machine of a character shown, forexample in Patent #1334376, issued November 14, 1933, or Patent#2,069,l07, issued January 26, 1937.

For an illustrative purpose, the finished broaching and shavingoperation to be successively carried on this machine are shown appliedto the finished machining of the four line bearings, flange end, andstud end of a typical six throw four line bearing multi-throwcrankshaft, shown in the Figures X, XI and XII. This crankshaft has theline bearings M, IS, IS, and I1, and the stub end 18, and flange end l9,comprising the line bearing portions of the crankshaft to be finishbroached and shaved by this lathe. The crankshaft has pin bearings 20 to25 inclusive, which are interconnected with themselves and with the linebearings by means of appropriate interconnecting webs 26 and 34,inclusive.

Referring to Figures X, XI, and XII, the machining to be done on thecrankshaft line bearing portions at work station one is that ofsimultaneously applying a series of face broaching tools, FB, carried onappropriate tool feeding devices 35, 36, 31, 38, 39, 40, and 4| whichare arranged to be actuated so as to feed the broaches FB substantiallytangentially of the diameter portion D, Figure XVI, of the various linebearings so that their cutting teeth 42 travel in a plane indicated bythe line XV--XV of Figures V and XVI. These face broaches FB havecutting edges 42a on their sides which are arranged to engage thevarious radially extending face portions 43 of the line bearings and theflange I9, and the oil groove 44 and chamfer 45 of the stub end of thecrankshaft to thereby simupltaneously complete the finishing to accurateaxial spacing of these surfaces for proper register with the cooperatingparts of the internal combustion engine in which the crankshaft is to beplaced. The various broaches F3 are fed as indicated in Figures V andXVI, the line bearing portions being positions relative to the broachesat 46 at the beginning of the cutting operation and reach the position4! after the'broaches have been fully fed past the line bearing portionsof the crankshaft to complete the broaching of the radially extendingface portions 43 of the line bearings.

The crankshaft C is then moved to work station two by the rotation inindexing movement of the drum 1 where the machining comprises that ofsimultaneously feeding a series of diameter broaching tools as bestshown in Figures V, XI,

XVII, and XVIII. These diameter broaching tools DB are carried onappropriate tool feeding devices 48, 49, 50, 5|, 52, and 53 so thattheir cutting teeth 54 feed tangentially past the diameter portion D ofthe various line bearings in I a plane indicated by the line XVII-XVII.of Figures V and XVIII. The relative position of the work crankshaft atthe beginning of the diameter broaching operation is shown at theposition 55 of the line bearings in Figure XVIII and at the completionof the diameter broaching operation is in the relative positionindicated at 56 in this figure. At this work station two the diameterportions are broached to an initial finished dimension of relativelyhigh accuracy, and may be considered as an initial finish broachingoperation preparatory to the final sizing of these portions to veryaccurate dimensions at Work station three. I

Having thus completed these broaching operations the work C is thenindexed to work station three" where the finish machining of the linebearings of the crankshaft consists in applying a series of shavingtools S to the finish broached diameter portions of the crankshaft so asto bring their final dimensions to an extremely high degree of accuracyand finish. By tangentially feeding these series of shaving tools S asshown in Figures V and XIII in a tangential plane substantially asindicated by the line XVI-XVI on these figurea. These shaving tools arecarried on appropriate tool feeding devices 51, 58, 59, 60, GI and 62which effect the proper tangential feeding movement in the variousshaving tools S in the plane XIV-XIV. In this last Work station threethe final accurate sizing of the line bearing diameters is accomplishedby the removal of any irregularities in these work surfaces as caused bythe diameter broaches DB at the work station two" so that the resultingfinish and accuracy of these diameter portions is of extremely highquality.

These shaving tools are of the typical shaving tool constructioncommonly used in machine tool practice having their cutting edgesarranged at an angle to axis of rotation 63 of the work piece andfeeding in the tangential plane XIVXIV relative to the diameter of thework surface to be cut so that the cutting edge of these shaving toolsprogressively travel relatively axially across the work surface so as toproduce a highly accurate finished surface on the various line bearingportions.

The work C is rotated at a predetermined speed at each of the workstations and independently of the speeds being effected at the otherWork stations. In this particular disclosure the Work spindles arerotated at relatively high speed while at work station "one and at workstation two, while the work is rotated at relatively low speed at workstation three," during the finish shaving operation. Means are providedfor automatically causing these spindles to rotate at the predeterminedspeed for each of the work stations independently of one another, thoughoperating simultaneously during the cutting operation between eachindexing cycle of the drum 1. In this way the broaching operations atwork stations one and two are carried on at relatively rapid spindlespeeds while the final finishing operation by the shaving tools is beingperformed at static-n three at relatively low spindle speed to effect aver high degree of finish on the work diameters machined at this laststation.

All of the tool feeding devices pointed out in Figures X, XI, and XIIand as shown together in Figure V, operatesimultaneously by suitablemechanisms to be described so that machining operations aresimultaneously performed at all three of the work stations during thecomplete cuttin cycle of the machine.

It is to be clearly understood that this machining procedure is welladapted to machining crankshafts from the rough forgings byappropriately constructing the broaching tools at work station one andwork station two to accommodate the additional material that must beremoved when rough forgings are to be machined. For instance, it is wellwithin the scope of our invention to add one or more work stations andwork spindle to the above outlined procedure, for the preliminaryroughing out of the work piece with suitable broaching apparatus. Also,We may utilize two or more center drive chucking devices ID in housings8 for each work spindle and utilizing a chucking method outlined forexamplein Patents 1,843,359, 1,934,976, and 2,030,020, or any othersuitable chucking device which might be used for gripping the crankshaftby means of roughing the unmachined webs. We might also incorporate aloading device as illustrated in our Patent 1,700,721 to facilitateloading of the work in the center drive work spindles. We have thusabove set forth the general nature of the machining to be done in thislathe, and We will now proceed with the detailed description of theoperatin mechanism and functions performed by this machine to carry outthe machining operations on the work piece above.

Drive for work spindles Noting Figures I and IV, the source of drivingpower for rotatin the work spindles is derived from the main driveelectric motor 64, mounted on the bracket 65 attached to the base I ofthe machine b suitable screws 66. This motor has the usual pinion 61adapted to drive the gear 68 carried on the main lonigtudinal driveshaft 69, appropriately carried in a bearing 10 in the trunnion II atthe right hand end of the drum 1.

This shaft 69 extends to the left end of the drum 1, as that shown inFigure IX, where it is con nected by suitable splined shaft connectionI2, with the central shaft I3, journaled in bearings I4 and I5 in theindexing housing I6, which housing is appropriately fixed on the flangeportion IA of the drum 1 by suitable screws 11. On this central shaft I3are fixed the small pinion I8 and the larger gear 19. The gear I8simultaneously engages the four gears 80, rotatably journaled onsuitable bearings 8| on each of the work spindle drive shafts 82 whilethe larger gear I9 simultaneously engages the smaller gears\83 alsorotatably journaled on suitable bearings 84 on these drive shafts 82, sothat with constant speed of rotation of the drive shaft 69 by theconstant speed motor 84, the gears 80 will be rotated at relatively slowspeed whereas the "gears 83 will be rotated at relatively high speed onthe various drive shafts 82. Associated with each of the series of gears80 and 83, are the respective clutch mechanisms indicated at 85 and 86,whereby the respective gears 80 and 83 may be alternately connected ordisconnected with respect to the various drive shafts 82, so that whenclutches 85 are engaged the drive shafts are rotated at relatively slowspeed from the shaft 69 and when the clutches 86 are engaged to connectthe gears 83 with their drive shafts 82, these drive shafts 82 will berotated at relatively high speed.

Suitable actuating mechanism comprising the shifting shoe 8! actuated bythe shifter yoke 88 fixed on the sliding shifter rod 89 carried in thehousing 16 serve to engage one or the other of the clutches 85 and 86 orto render both of said clutches inoperative when moved to anintermediate position between the clutches.

The ends of these shifting rods 89 are provided with enlarged cam ends89a as best shown in Figures II, VII and IX, in which operate a seriesof fixed cam rollers 90, 9 I, 92, and 93, which are carried onappropriate studs 94, fixed in the upright support 2 of the machineframe. These studs 94 are variously axially projecting from the lefthand face of the support 2, so as to effect an automatic shifting of theshifter bars 89, as the drum I and the housing I6 are rotated inindexing motion to carry the Work spindles from one work station to thenext. For instance, in the particular construction and arrangementillustrated in this case wherein it is the object to provide relativelyhigh speed of rotation for the work spindle while at station one andstation two and relatively low speed at station three, the rollers 90and 9| are carried on their respective studs projecting only a shortdistance out from the support 2, so that as the cam ends 89A of the rods89, move past these rollers, they will be positioned as shown at 90 and9| in Figure VII, so as to move the rod 89 to the right Figure IX toeffect engagement of the clutch 86 for high speed drive through thegears I9 and 83 to the drive shafts 82 when their associated workspindles are at work station one and two. The rollers 9| and 92 engagethe cam surface 893 and ultimately ride up on the cam surface 890 as thedrum 1 is indexed from loading station up to work station one. When thedrum indexes a work spindle to station two the rod 89 will remain to theright, Figures VII and IX, sirice the roller 9| is positioned the sameas the roller 90 to maintain this high speed driving relationship atwork station two."

However, when the drum indexes to station three the roller 92 carried onits stud 94 projects far to the left from the support 2, so that it willengage the surface 89D and will thereby ultimately move the rod 89 tothe left to the low speed position, the roller eventually riding up onthe surface 89E as shown in Figure VII to effect operation of the clutch85, thereby effecting a low speed drive between the gears I8 and forrelatively slow rotation of the drive shafts 82 for the work spindlewhen at work station three.

As this spindle again rotates back to the loading station, the roller 93carried on its stud 94, projects to an intermediate position betweenthat of the rollers 9I and the roller 92, so as to return the rodsomewhat to the right to a neutral position at which time neither of theclutches 85 and 86 are operative as is shown in Figure VII. Thus as theworks spindle finally arrives back at the work station, it isautomatically stopped from rotation and also at the same time, as thisspindle rotates into the work station an automatic braking device comesinto play to prevent coasting rotation of the spindle so that theoperator may promptly get at the unchucking of the work from the spindleand the reloading of Work in the spindle for the next cycle ofoperation.

This braking mechanism is shown best in Figures II and IX and comprisesa spring urged shoe carried on appropriate studs 96 on the bell shapedmember 91, which is journaled on the bearing surface 98 of the housingI6 and is prevented from rotating with the indexing of the drum 7 andthe housing I6 by the link 99 connected to the hydraulic reservoir tankI00 fixed on the base I by screws II8 by a suitable pin IIlI andattached to the lugs I02 of the member 91, so that it does not rotatebut floats on the bearing surface 98 of the housing I6, thus maintainingthe brake shoe 95 in proper oriented position with respect to theindexing position of the drum I and housing I6. This brake shoe 95 isadapted to engage the brake drums I03, one of which is fixed on each ofthe drive shafts 82 and which drums I03 engage the brake shoe at theprecise time that its respective work spindle is brought to the loadingstation. Suitable springs I04, serve to automatically allow the shoe toride up on to the brake drums I03 as they index into the loadingstations and also to provide sufficient braking pressure to permit thespindle to be rotated under manual operation when at the loadingstations while at the same time providing sufficient friction forquickly arresting rotation of the works spindle when brought to the workstation. In regard to this braking device, this arrangement issubstantially like that shown in applicants prior Patent #2,l38,522dated November 29, 1938.

The manual operation of the work spindles when at the loading station isprovided by means of the control handle I05 journaled, as best seen inFigures VI and VIII, on a suitable rock shaft I06 carried in the bracketI01 fixed to the front of the housing 2 of the machine. On this rockshaft I06 is mounted a gear I08 which engages a rack I89 on the slidablymounted stud |I0 carrying the roller III which is provided in the samepath as followed by the ends 89A of the shifter rods 89 which engage thevarious rollers 90, 9|, 92 and 93. The movable stud H0 is so positionedthat when the work spindle is in the loading station, its roller will bepositioned around the roller III shown in Figure VII so that the lever Iwhen swung to the position III5A, Figure VI, it will effect the highspeed operation of the work spindle and when swung to the position IIISBwill effect theslow speed operation of the work spindle at the workstation. When in the verticalposition shown in Figure VI the respectiverod 89 then stops rotation of the work spindle and the rapid coasting ofthe work spindle and rapid deceleration thereof will be affected by thebrake shoe 55 operating on the brake drum I03 as described.

The various drive shafts 82 are respectively connected to the centerdrive ring gears 9 of each of the 4 work spindles as best shown inFigures III and IX. Each of the drive shafts I Indexing mechanismMechanism for rotating the work spindle carrying drum "I. to therespective indexed positions of the .various work stations and theloading station comprises a fluid pressure driven indexing motor II Ibest shown in Figures I, II, and XIX, suitably fixed to the oilreservoir IIJIl having a driving pinion H9 secured to the power output--shaft. A compound gear, comprising the large gear I28 meshing with themotor pinion I I9 and the small gear I2I meshing with the. largeindexing gear I22, is suitably supported on a stud I23, fixed to theframe 2 of the lathe. This arrangement afiords a meanswhereby the fluidoperated indexing motor II? is adapted to re volve the drum 1 throughthe large gear I82,

whichis fixed to the flange portion 7A of the drumgIof thelathe.

A fluid pressure actuated indexing plunger mechanism is provided fordefinitely positioning 5 in the line of feeding indicated by the linebreaching and shaving tool feeding devices and 4 the indexing motor II!and cylinders I and I32 for the indexing'plungers is derived from thefluid pressure pump I35 in the reservoir I00 which is driven by asuitable electric motor I36 to supply pressure to the feed cylinder I31,Figure IV, fastened to the base I of the lathe; Attached to thereciprocatable pistonrod I38 of this cylinder by suitable connectingmeans I 39 is the rack I40 which is carried inappropriate guide ways Iin the bracket I42 fixed to the side of the upright support 3 of'thelathe. This rack I4ll engages the large segmental feed gear I43, whichis journaled about the trunnion-II of the drum I and'engage'sthe'various feed pin- '7 ions I44, I45 and I46.v The gear I44 is fixedon the feed shaft I41 which is appropriately journaled in the housing 4and carries on it pinions I48, Figure V, one for each ofthe-face'bro'aching slides I49 and I50 shown in Figure I. These pinionsI48 engage appropriate racks I5I- fixed on each of these slides I49 andI5!) so asto eflect the feeding of the tool feeding devices of FigureXVXV as described. The gear I54 is mounted on the feed shaft I52, whichis journaled in a housing I53 mounted on the base I between the uprightsupports 2 and Send this shaft carries suitable pinions I55 which engageracks I55 on the drum I and work spindles carried thereon in properposition relative to the work stations and work loading position, thismechanism being interlocked with the operation of the fluid indexingmotor I I? in a manner to be described. This indexing plunger i23A ismounted for sliding.

movement in a bracket I23 fixed to the left hand side of the uprightsupport 2 by suitable screws 524 and is arranged to be actuated by meansof a suitable hydraulic cylinder I25 also carried on this bracket I23.This indexing plunger IZSA has the usual chami'ered end I26 which isarranged to engage the various indexing slots I2? formedon the gear I22of the indexing blocks I28 bolted thereon by the screws I29, there beingone of these blocks'with an indexing notch i2? for each of the 4 indexedpositions of the drum 7.

An additional indexing and ste'adying device is provided asbest shown inFigure III which comprises a fluid pressure actuated plunger ISI carriedin the housing 5 and which is actuated by a suitable hydraulic cylinderi32 in synchronized relationship with the indexing plunger IZ3A justdescribed. This plunger i3i is adapted to engagein the respectiveindexing holes. I33 in each of the center drive housings B when the drumI has been moved to an indexed position.

Tool feeding mechanism The driving power for moving the various Elislides IE IA similar to those mounted on the housing 4 to efiect feedingmovements in the diameter breaching tool feeding devices along the linesXVII-XVII of Figure 5 as described. The gear I46 is appropriatelymounted on a stud I56 fixed to the base Iof the lathe and has connectedthereto a pinion I5I- to'rotate with it which drives an idler gear I58also journaled on a stud E56 fixed in the base I of the machine.

tion threeifi This shaft IEI is journaledin an appropriate housIng'IBZ,also mounted on the base I of the lathe, between the upright supports .2and 3. On this shaft ISI are fixed pinions I63 which engage racks I64fixed on the shaving tocl slides I and I 66, shown in Figure I, so as toeffect the feeding of these shaving tools 8 along the lines XIV -XIV asshown in Figure m. It can thus be seen by this arrangement,

actuation'of the segmental gear by the cylinder I3! effects simultaneousfeeding of the broaching tool feeding devices at stations one" and two"and the shaving tool feeding devices at station three along the lines offeeding indicated in Figure V.

Operation and control The operation of this machine is substantially asfollows: Referring particularly to Figure I, assuming a crankshaft ,tobe machined has been properly inserted in a work spindle at the loadingstation with its ends supported on the centers 53 of the tailstocks IIand suitably gripped intermediate its ends in the chucking mechanismThis J idler gear I58 in turn drives a gear I60 which.

is carried on the feed shaft IGI for the work stathe feed" cylinder I31.

I85 from entering line I88 thus rendering the hydraulic motor II1momentarily inoperative for releasing strain on the indexing plungerI23a soit may be withdrawn from a slot I21 by energizing at the sametime the solenoid I18 of control valve I 19 which connects fluidpressure from line I80 and I8I to the line I82 to actuate the cylinderI25 to withdraw the plunger I23a. Exhaust fluid from this cylinder I25passes through line I92, through the valve I19 into the drain line I89.Also at this time, the tool slides being fully withdrawn, the dog I94 onthe segmental feed gear I43 engages the stem of the control valve I95permitting fluid pressure from the lines I12 and I98 to enter line I98to withdraw the plunger I3I from the hole I33 in the center drive head8, exhaust fluid from this cylinder passing out through line I91, thevalve I95 into the drain line I11.

The withdrawal of the indexing plunger I23a causes its dog I93 to engageand actuate the limit switch LS-2' which, through conventionalelectrical apparatus, deenergizes the solenoid I83 and energizessolenoid 205 to actuate the valve I84 to deliver fluid pressure to theindexing motor I I1, exhausted fluid from this indexing motor passingout through line I81, through'the normally inoperative decelerationvalve I88 into the drain line I89 to cause the drum 1 to index to bringthe loaded work spindle to work station "one."

As this indexing motion proceeds the dog 20I on the indexing gear I22actuates the limit switch LS-8, but atthis time thislimit switch/ isrendered inoperative by the limit switch LS-4 which is now beingactuated by the dog 204 on the rack I 40 with the tool feeding devicesfully retracted so that the indexing movement continues uninterrupteduntil the dog I90 fixed on the indexing gear I22 depresses the plungerof 40 the decelerating valve I88 which restricts the discharge from theindexing motor I I1 to thereby reduce the rate of indexing of the drum11 just before the indexing plunger I230 again is ready to enter thenext indexing slot I 21. With the indexing motion taking place at thisdecelerated rate, a dog 203 is provided on the indexing gear"I22 toactuate the 'limit'switch LS-3 just as the notch I21 comes into properregister with the indexing plunger I230; to at that instant energizesolenoid I9I of control valve"i19 causing the index plunger I23a to bethrust into the indexing notch I21 The spindle, now loaded. has thusbeen positioned at work station one and as a resultof inserting theindexing plunger I23ainto the 1 notch I21,.i ts dog I93 actuates thelimit switch LS-I which in turn causes the solenoid I88 of r .thefeedcontrol valve I89 to he energized whereupon'the valve I89 is'actuated soas to connect fluid, pressure from the fluid pressure pump I35 throughthe line I10, the pressure relief valve HI, and line I12, through thevalve I89 to the line I13, which is connected to the bottom of Thiseffects upward or feeding movement of the cylinder rod I38 and rack I40connected to the piston of this feed cylinder. The rate of upwardmovement or feeding rate of this cylinder rod I38 is determined by theescape of fluid from the rod end ,0! the cylinder I31 through the lineI14, the feed rate control valve I15, which re ulates the dischargethrough the line I14, into the line I18, and thus to the control valveI89 to the drain line I11, thus back to the fluid reservoir I00. As soonas this cylinder I31 begins its feeding operation the dog I94 on thefeed segment gear I43 actuates the control valve I95 whereon fluidpressure is delivered through the line I98 through the valve to the lineI91 connected to the indexing plunger cylinder I32 for moving the centerdrive housing indexing plunger I3I into the socket I33 in the centerdrive head 8. Exhaust fluid from this cylinder I32 passes out throughline I98, the control valve I95, and into the drain line I11. Also atthis time fluid pressure is maintained in the hydraulic motor II1 by thecontinuous energizing of solenoid 205 of valve I84 holding the gear I22and drum 1 against the indexing plunger [23a in the notch I21 to preventany shake or back lash in this mechanism.

The feed cylinder I31 continues its upward feeding movement rotating thesegmental gear I43 and actuating the various feed shafts I41, I52

and I8I to actuate the breaching slides at work stations "one" and two"and the shaving tools at work station three.". Also, as pointed out, asthe work spindles in which the work was loaded is indexed to station"one," the roller 90 on the stud 94, Figure II, effects operation of theclutch 88 Figure'IX causing the spindle to operate at high speed at thiswork station. This forward feeding motion continues and at thecompletion of this motion a dog I99 on the rack I40 engages so a limitswitch LS-5 which causes solenoid I18 of the control valve I19 to beenergized for withdrawing the indexing plunger I23a and at the same timemomentarily energizes the solenoid I83 to release the hydraulic indexingmotor H1 from driving the gear I22 to permit easy withdrawal of theindexing plunger I23a from the indexing notch I21 in the ring gear I22.Also, the solenoid 200 of the valve I98 is energized to effectwithdrawal of the plunger I3I from the center drive housing 8 byconnecting fluid pressure from the line I92 to the line I98, exhaustfluid passing out through the line I9I into the drain line I11.-

Withdrawal of the index plunger I23a causes its dog I93 to actuate thelimit switch LS-2 5 which in turn energizes the solenoid 205 of thevalve I84, starting up the indexing motor ill to rotate the gear I22 anddrum 1 while the tool feeding devices remain at their fully fed inposition.

This indexing motion continues for a partial distance of travel of thedrum 1 to the next work station until the dog 20I on the gear I22engages the limit switch LS-B, the actuation of which energizes thesolenoid I03 of the valve I84 stopping rotation of the indexing motor II1 and drum 1 and also energizes the solenoid 202 of the control valveI89 whereupon fluid pressure from the line I12 is applied to the lineI18 freely through the feed rate valve I15 and the line I14 to the rod60 end of the feed cylinder I31, quickly returning the rack I and thefeeding devices to their withdrawn position, exhaust fluid passing outthrough the line I13 to the control valve I89 into the drain line I11.

As the tool feeding device and the feed cylinder I 31' return to thefully withdrawn position as shown in Figure XIX, a dog 204 on the rack I40 actuates the limit switch which energizes solenoid 205 of the valveI84 to again effect operation of the indexing motor I I1, continuing theindexing of the gear I22 and drum 1, and the deceleration of thisindexing motion by the deceleration valve I88 and the ultimate insertionof the indexing plunger H31: in the next indexing notch I21, asdescribed, thus bringing the device interconnected between said workspindle to work station two. This same cycle of operation takes place inbringing this work spindle to work station three and back to the loadingstation where the finished work piece is removed and an unmachined workpiece is again loaded in this spindle.

The detailed description of the conventional electrical apparatusinterconnecting the limit switches and the solenoids of the controlvalves is not set forth as this apparatus is well known in this art andforms no part of this invention.

The object of this delayed indexing motion is to permit the drum to beindexed away from working position so that the broaching tools may bewithdrawn from the work pieces before the indexing continues to the nextstation so that during this indexing motion the tool will not mar andscratch the work as the work i indexed out of cutting position to thenext station. Thus in this arrangement we have provided a broachinglathe in which the work is indexed from station to station and in whichthe work is indexed partially.

out of work engaging position at the work stations while the toolfeeding devices are fully fed in position and then, after the tools havebeen removed to fully retracted position, the indexing is continued tobring the work to the next station.

Having thus fully set forth and described our invention, what we claimas new and desir to secureby United States Letters Patent is:

1. In an indexing mechanism, an indexing carrier, an indexing motorconnected to said carrier for rotating said carrier to indexedpositions, a source of power for driving said motor, a control motor andsaid source of power for connecting or disconnecting power from saidmotor, and means actuated by the movement of said indexing carrier toactuate said control device so as to effect a partial indexing of saidindexing carrier by momentarily arresting operation of said indexingmotor by disconnecting power therefrom before completing the indexingoperation by further ap plication of power to aid motor.

2. In an indexing mechanism an indexing carrier, an indexing motorconnected to said carrier for rotating said carrier to indexedpositions, a source of power for driving said motor, a control deviceinterconnected between said indexing motor and said source of power forconnecting or disconnecting power from said motor, and means actuated bythe movement of said indexin indexing rier to actuate said controldevice so as to effect a partial indexing of said indexing carrier bymomentarily arresting operation of said indexing motor by disconnectingpower therefrom before completing th indexing operation by furtherapplication of power to said motor, and a decelerating control deviceinterconnected between said indexing motor and said source of power forrestricting power flow to said indexing motor when actuated by theindexing move.- ment of said carrier so as to regulate said indexingmotor to cause said carrier to move at a predetermined slow rate duringthe completion of said indexing of said carrier.

3. In an indexing mechanism, an indexing carrier, a hydraulic indexingmotor connected to said carrier for rotating said carrier to indexedpositions, a fluid pressure pump connected to drive said indexing motor,a control valve interconnected between said indexing motor and saidsource of power for connecting or disconnecting fluid pressure from saidmotor, means ior actuating said control valve by the movement of saidcarrier so as to effect a partial indexing of said carrier bymomentarily disconnecting fluid pressure from said indexing motor beforecompleting the indexing of said carrier by again applying fluid pressureto said motor.

4. In an indexing mechanism, an indexing carrier, a hydraulic. indexingmotor connected to said carrier for rotating said carrier to indexedpositions, a fluid pressure pump connected to drive said indexing motor,a control valve interconnected between said indexing motor and saidsource of power for connecting or disconnecting fluid pressure from saidmotor, means for actuating said control valve by the movement of saidcarrier so as to efiect a partial indexing of said carrier bymomentarily disconnecting fluid pressure from said indexing motor beforecompleting the indexing of said carrier by again applying fluid pressureto said motor, and a decelerating control valve interconnected betweensaid fluid pressure pump and said indexing motor for restricting powerflow to said indexing motor when actuated by the movement of saidcarrier so as to cause said motor to operate at a predetermined slowspeed during the completion of said indexing of said carrier. I

WILLIAM F. GRIOENE. HAROLD J. SIEKMANN.

